Aquarius: Sea Surface Spiciness from Satellite Radiometry

NASA's Aquarius satellite, a joint mission with Argentina's CONAE, used three radiometers and a scatterometer to measure ocean salinity via brightness temperature at 1.413 GHz. This Level 3 dataset provides the mission-cumulative mean of sea surface spiciness, a water density property, at a 1-degree spatial resolution, derived exclusively from the satellite's descending passes. The data is processed into daily, 7-day, monthly, and seasonal averages for analysis of ocean density structure and climate-related processes.

Use Cases

• Analyzing ocean density structure and water mass formation based on gridded spiciness data.
• Studying seasonal and interannual variability in ocean surface properties using daily to seasonal time scales.
• Validating and improving ocean circulation models with satellite-derived salinity and density products.
• Investigating the relationship between sea surface roughness and salinity retrieval using scatterometer backscatter data.

Strengths

• Data originates from a dedicated satellite mission (Aquarius/SAC-D) with a specific instrument suite of three radiometers and a scatterometer.
• Provides a consistent, mission-long cumulative product (Version 5.0) for the Descending pass, simplifying trend analysis.
• Offers multiple temporal aggregations (daily, 7-day, monthly, seasonal) from the same source.

Limitations

• Key metadata is missing: specific column names, row counts, and file sizes are not provided on any platform.
• There is a significant conflict in reported freshness: one source lists a last update in 2026 (likely an error or placeholder), while another shows 2015, casting doubt on ongoing maintenance.
• The dataset is limited to Descending pass retrievals, omitting the full diurnal cycle captured by Ascending passes.

Provenance

Source

National Aeronautics and Space Administration (NASA) and Comision Nacional de Actividades Espaciales (CONAE, Argentina).

Collection Method

Satellite remote sensing via the Aquarius instrument on the AQUARIUS/SAC-D platform, using L-band radiometers and a scatterometer.

Time Range

Mission series cumulative mean (coverage corresponds to the Aquarius mission lifetime).

Freshness

Conflicting: One source reports last updated 2026-03 -13 (likely erroneous), another reports 2015-06-07.

Geography

Global ocean coverage within the instrument's 370 km cross-track swath.